This invention generally relates to a method and system for sensing a side collision. More particularly, this invention relates to a system and method for adjusting an acceleration threshold value responsive to a measured vehicle lateral velocity.
Vehicles including active occupant restraint systems such as air bags include a plurality of sensors disposed throughout the vehicle to detect a crash or collision condition requiring actuation of specific restraint systems. The occupant restraint system verifies measurements from one sensor through measurements from another sensor to protect against undesired actuation caused by sensor failure. However, a lateral collision, for example, a side impact with a pole, is a very local event, the immediate effects of which are measurable over a limited area of the vehicle. Therefore, sensors disposed in areas distant from the impact area may not indicate collision conditions to the magnitude required to verify the sensor reading in the area of impact to cause activation of the occupant restraint system.
One current method of countering such performance is to decrease the threshold value required to cause actuation of the occupant restraint system. Unfortunately, the threshold value may be required to be lowered to such a level so as to cause actuation of the occupant restraint system for static abuse conditions, such as for example, rocking of a vehicle, slamming a door, or an impact by a shopping cart.
Disadvantageously, once the occupant restraint system is actuated, (e.g. the air bags are explosively inflated) they must be replaced and repaired at a significant cost.
Accordingly, it is desirable to develop a method and system that discerns between a true lateral collision and a static abuse situation to prevent undesired actuation of an occupant restraint system.